Mounties didn't respond and, 12 days later, on Feb. 25, 2005, they found Moreside's bloody body in her bungalow in High Prairie.
Cynthia and Craig Flaata buried and mourned their mother, unaware she had called police in the moments before she was stabbed to death.
After nearly a year, they heard about it from a reporter. An internal RCMP memo leaked to the media revealed the 44-year-old woman had dialed 911, but police wouldn't respond because the man couldn't be charged with breaking into his own residence.
At the time, RCMP admitted they made an error: an officer should have been dispatched.
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On Monday, a fatality inquiry is to start to examine the circumstances of Moreside's death. Mounties will be called to testify and, it's expected, a recording of the crucial 911 call will be played.
Moreside's children say they don't want to hear the tape and her last plea for help. Nor are they interested in the disturbing details of her death. But they do want some answers from the RCMP, including whether anyone was ever disciplined for the decision not to respond.
The also want an apology.
"They don't respect us enough to tell us anything," said Craig Flaata, who added that his many letters to the force have gone unanswered. He's angry and blames the Mounties for his mother's death.
"I think the RCMP need to be held accountable. If they sent someone, she could still be alive now."
Moreside, who had her first child at 17, was divorced and had moved around the province before settling in High Prairie, about 360 kilometres north of Edmonton. She had been in several bad relationships before she met Stanley Willier from the nearby Sucker Creek reserve in about 2001.
They were engaged to be married, but her children hoped the relationship wouldn't last. Moreside often ran off to see her kids in Edmonton after nasty fights with Willier. One time, she told them, Willier had kicked her down some stairs, breaking some of her teeth.
They begged her to leave him.
The night before Moreside was killed, the couple had been out drinking at the Cozy Corner Pub in High Prairie, said Cynthia Flaata. The two had an argument at the bar before Moreside went home and locked Willier out.
From sitting through various legal proceedings in the case, Cynthia Flaata learned that her mother actually called police two times that night. News reports on the leaked RCMP memo said an officer phoned back Moreside that night and asked if she felt like she were in danger. She said no.
Flaata can't explain why her mother waved off police.
Perhaps her killer was already threatening her?
It's more likely the woman just got fed up asking police for help, Flaata suggested.
"I think probably because it was a hassle to get a response, they weren't taking her seriously ... she was like, 'You know what. Forget it. I'll just deal with this guy myself.'"
Nearly two weeks later, she said, Willier told a relative he had done something awful to Moreside. Police were alerted. That's when they found her body.
Willier was arrested and later confessed to the crime. But Moreside's family would soon have another reason to be angry with the Mounties.
In 2006, a judge tossed Willier's confession, ruling that he hadn't been given a reasonable opportunity to consult with a lawyer of his choice before the police interview.
He was set free.
The Court of Appeal later ruled the Mounties weren't so wrong after all and ordered a new trial. Willier took his case to the Supreme Court, but lost. In 2011, Willier pleaded guilty to manslaughter and was sentenced to 10 years.
It was his second conviction for manslaughter. He had already killed a man in a rooming house brawl, something RCMP should have known about when Moreside called 911, said her daughter.
She hopes the inquiry will also question the RCMP about whether race played a role in their decision that night. Moreside was Metis and Willier is from a First Nation.
Did police think they were just "a couple of drunk Indians?" asked Flaata.
"I don't want to say that it is a race thing, but I don't know that it isn't a race thing. Did that play a part in it? I'd like to know. If it was somebody from one of the white, rich families back home, would they have gone out to that house to make sure the husband wasn't going to hurt her?"
Craig Flaata said that in a small town such as High Prairie, with just 3,000 people, the RCMP detachment isn't far from anywhere and it would have taken only minutes for officers to get to his mother's house and save her.
His sister agrees, but wonders what would have happened after that?
She believes Willier would have killed her mother at some point. "Who knows if it would have been three months later, a year later ... Stan at the end of the day is the man who chose to make that decision in the heat of the moment to kill my mom. But my mom also chose to stay."
RCMP wouldn't comment on the case before the inquest starts.
After news leaked out about the 911 call, the force did say High Prairie officers would receive additional domestic violence training. They were also to review 800 family violence files but wouldn't say if the review led to any further charges.
Cynthia Flaata said witnessing her mother's abuse has made her unwilling to accept any mistreatment at the hands of a man. And she's instilled that attitude in her teenage daughter.
While her brother is still angry about their mother's death, she is more resigned.
So many years have passed, she's had to find closure on her own.
"I'm not angry anymore. I'm just more curious as to what went wrong."